Sphygmomanometer measuring tube ejection mechanism



G. H. JONES May 2, 1967 SPHYGMOMANOMETER MEASURING TUBE EJECTION MECHANISM Filed March 50, 1965 INVENTOR George H. Jones ATTORNEYS 3,316 766 v SPHYGMOMANOM ETE R IWEASURING TUBE EJECTION MECHANISM George H. Jones, Mass'apequa, N.Y., assignor to W. A. lgzmin Co., Inc, Copiague, N.Y., a corporation of New or r Filed Mar. 30, 1965, Ser. No. 443,926 2 Claims. (Cl. 73-402) This invention relates to sphygmomanometers of the mercury-manometer type having replaceable measuring tubes, and to an improvement in the means for removing and replacing such tubes.

As is known, the sphygmomanometer art is well advanced so that in a typical instrument both the mercury reservoir and the measuring tube may be standardized as to their interior diameters. All tubes, at the time of their manufacture, may be calibrated while coupled with a master reservoir, resulting in free interchangeability of tubes in all instruments while retaining constant accuracy of readings. Also, progress in the design of such apparatus has made the replaceable tubes more accessible, so that the user himself can make the substitution when a tube becomes broken, as from normal operation hazards.

Such tubes must be transparent for functional reasons and are usually made of glass; thus they are somewhat fragile, and handling of them is likely to be exercised under less than optimum conditions for their safety. A principal object of this invention is the improvement in means relating to said tubes to facilitate ease, speed, and safety of their removal and replacement.

This invention combines a releasing mechanism and an ejection mechanism which function simultaneously to partially eject the measuring tube at the time of its removal. In many conventional sphygmomanometers, the tube in its ordinary position is partly recessed in a groove; thus merely releasing its ends doesnt adequately affect its removal. The user must then tilt the housing or otherwise dislodge or extricate the tube, with a likely consequence of dropping the tube or spilling the measuring fluid. The groove in this particular type of embodiment is relatively important as it partially encloses the tube affording protection from ordinary yet dangerous contacts, while permitting great visual access of the tube to the user.

According to the invention of this application, an ejection means, comprising for example a spring-biased pin, is disposed in contact with the outer surface of the measuring tube, intermediate its ends. A spring-pressed cup adjacent the upper end of said tube and engaged thereto ordinarily exerts an axial force on the upper end of said tube causing mercury-tight connections at both ends of the tube. When said cup is raised to release the ends of said tube from retaining pressure, the ejection means urges the tube outward to a more accessible location. The user is then able to grasp the extended tube; this is a far easier and safer maneuver than attempting to dislodge it by conventional means. Thus this invention has provided an improvement that has both important value and useful convenience to users of sphygmomanometers.

The features disclosed above, and others will be described in more detail in the following description of the preferred embodiment of this invention, when considered in conjunction with the drawings in which:

FIG. 1 is an exploded front perspective view of the sphygmomanometer,

FIG. 2 is a fragmentary side elevational view thereof, and

ited ates Patent 3,316,766 Patented May 2, 1967 FIG. 3 isan enlarged cross-sectional view of the ejection mechanism.

Referring to the drawings, FIG. 1 shows an assembled sphygmomanometer with the measuring tube 2 rigidly attached by its ends within the housing 1, generally in the front surface thereof. More specifically the tube is partial= ly submerged within groove 3.

FIG. 2 displays the measuring tube 2 more clearly in its relationship to the whole apparatus. FIG. 3 indicates the details of the ejection device of this invention. Measuring tube 2 is shown in its normal position, which is generally parallel to the axis of the fixture and restrained there intermediate connection 4 with the reservoir and spring-pressed cup 5 at its upper end. Cup 5 is shown in its displaced position, though being drawn at all times by tension spring 7 to return downward and hold tube 2 rigid. The displacement of cup 5 and consequent release of tube 2, is affected by the rotation of trigger lever 9, which is pivotally mounted within fixture housing 1. Lever 9 is shown in its rotated position opposing the force of spring 7 and by its contact with flange 10 of bracket 6, it has displaced cup 5. Lever 9 has a normal position 9a, which it would occupy when cup 5 is drawn downward by spring 7 to its assembled position.

Ejector pin 20 is slidably disposed through hole 24 in frame parts 11 and 22 and biased by spring 21 to urge tube 2 to its extended position 2a. When cup 5 is raised, clearance space 13 becomes available through which tube 2 may pass. The force of spring 21 assures that that tube will move outward to position 2a, and be readily accessible for operator to grasp for replacement.

I claim:

1. In a sphygmomanometer type having (1) a mercury reservoir standardized as to its essential interior dimensions,

(2) a replaceable measuring tube calibrated with respect to the reservoir, said tube having one end detachably connected to said reservoir,

(3) a fixture afliording communication between said reservoir and said measuring tube,

(4) said tube being interchangeable with another like measuring tube, and

(5) a spring pressed cup adapted to engage the opposite end of the tube to maintain the connection between the tube and reservoir mercury-tight, and to retain the tube in a fixed position, the improvement comprising in combination therewith,

(a) spring-biased means disposed in contact with the outer surface of the tube intermediate its ends, and

(b) means arranged adjacent the upper end of said tube for lifting said spring pressed cup whereby said spring biased means urges the tube outward to enable grasping the same for removal and replacement.

2. A sphygmomanometer as defined in claim 1 wherein the spring-biased means comprises an ejection pin slidably mounted generally normal to the axis of said measuring tube.

of the mercury-manometer References Cited by the Examiner UNITED STATES PATENTS 2,690,676 10/1954 Heuboski et al. 73-402 LOUIS R. PRINCE, Primary Examiner.

D. O. WOODIEL, Assistant Examiner. 

1. IN A SPHYGMOMANOMETER OF THE MERCURY-MANOMETER TYPE HAVING (1) A MERCURY RESERVOIR STANDARDIZED AS TO ITS ESSENTIAL INTERIOR DIMENSIONS, (2) A REPLACEABLE MEASURING TUBE CALIBRATED WITH RESPECT TO THE RESERVOIR, SAID TUBE HAVING ONE END DETACHABLY CONNECTED TO SAID RESERVOIR, (3) A FIXTURE AFFORDING COMMUNICATION BETWEEN SAID RESERVOIR AND SAID MEASURING TUBE, (4) SAID TUBE BEING INTERCHANGEABLE WITH ANOTHER LIKE MEASURING TUBE, AND (5) A SPRING PRESSED CUP ADAPTED TO ENGAGE THE OPPOSITE END OF THE TUBE TO MAINTAIN THE CONNECTION BETWEEN THE TUBE AND RESERVOIR MERCURY-TIGHT, AND TO RETAIN THE TUBE IN A FIXED POSITION, THE IMPROVEMENT COMPRISING IN COMBINATION THEREWITH, (A) SPRING-BIASED MEANS DISPOSED IN CONTACT WITH THE OUTER SURFACE OF THE TUBE INTERMEDIATE ITS ENDS, AND (B) MEANS ARRANGED ADJACENT THE UPPER END OF SAID TUBE FOR LIFTING SAID SPRING PRESSED CUP WHEREBY SAID SPRING BIASED MEANS URGES THE TUBE OUTWARD TO ENABLE GRASPING THE SAME FOR REMOVAL AND REPLACEMENT. 